jsHint cleanup
Story validation method for Story model

Add ``Story.validateStory()`` method for basic validation of
core story components.

This was named so it didn't conflict with ``Backbone.Model.validate()``
which has a different purpose.

Addresses #909
Only publish the story if it has requried components

Only publish the story if it has a title.  Show an error alert
if it's missing the title and a warning alert if it's missing other
fields.

This still needs to be tested in the browser and also needs more
refined alert and error messages.

Addresses #909
Refine story validation error and warning messages.

* Make the alerts persistant and sticky.
* List the missing fields in the messages.

Addresses #909